Friction-brake.



8. HQ KEEPER.

FRICTION BRAKE.

APPLICATION men MAR.Z4. 1910.

1,162,370, Patented Nov. 30, 1915.

'rn s'rnns PA OFICE.

SAMUEL HINE KEEFER; OF PLAINFIELD, NEW JERSEY, ASSIG-NOR TO NILES-BEMENT- POND COMPANY, OF JERSEY CITY, WW JERSEY, A CORPORATION OF NEW JERSEY.

FRICTION-BRAKE.

Specification of Letters Patent.

Patented Nov. 30, 1915.

v all whom it may concern.

Be it known that I, SAMUEL H. KEEFER, a citizen of the United States, residing in Plainfield, county of Union, Stateof New Jersey, have invented certain Improvements .in Friction-Brakes, of which the following i is a specification.

.The present invention has for an object the provision of an economical and reliable form of braking mechanism having its parts so arranged that under normal operating conditions neither of its co-acting braking members are in motion; the construction being such that only under conditions requiring the use of the brake, are these parts moved.

Another object of the invention is the provision of an 'eflicient, easily constructed and durable brake, particularly adapted for ap plication to a planer or other machine havprovide a friction brake whose co-acting.

ing a reciprocating part, which shall be of such a construction as to automatically come 1nto operation to stopmovement of such part when the driving mechanism ceases to act; as for example,when the current is cut off from the driving motor.v A further object of the invention is to friction surfaces shall have relative movement only at the time when said brake is. actually'ln use to retard movement of the apparatus to which it. is connected; the invention also contemplating 'a construction will be exemplified in the construction hereinafter set forth, and the scope of the application of which will be indicated in the following claims.

lnthe' drawings, illustrating a preferred embodiment of the several features of the invention, Figure 1 is a vertical section of a brake constructed in accordance with my invention and applied to the armature shaft of an electric motor; Fig. 2, is avertical section on the line 'aa, Fig. 1, and Fig. 3, is a diagram showing one arrangement of electrical connections between my improved braking mechanism and thedriving motor.

Similar reference characters refer to similar parts throughout the several views of the drawings.

Referring now to Fig. 1, there is represented atl a portion of the casing of an shaft is shown at 2, while the end of the armature is indicated at 3. Attached to the casing 1, either integrally or otherwise, and concentric with the shaft 2, is a fixed clutch member 4 having within it a winding 5, which with a plate 6 constitutes an electromagnetic clutch. While said clutch may be of any desired suitable construction, the arrangement of the parts is such that one of 1ts memb.ers,in the present instance the casing 4 and'the winding 5,is rigidly con nected to the stationary motor casing 1, while the iron or steel plate 6 forming the armature of the magnet is keyed or other- -wise mounted upon the shaft 2' so as to be compelled to turn therewith while being electric motor, one end of whose armature free to move toward or from' the casing 4 and its winding. Said winding has a protecting face plate 7 fastened to the casing 4 between it and the armature plate'6, and

this latter is normally held away from the adjacent face of the stationary clutch member 4 by means of a spring 8 mounted within the said member, preferably concentri with the shaft 2. I I

For connecting the armature plate 8 with the shaft, there is provided-a sleeve 9 slidably mounted on'said shaft and held from turning by keys 10. Said'sleeve, as shown in Fig. 2, is provided with teeth or projections 11 and is free to turn relatively to the thereto by means of a nut 12.-

The friction surfaces of the brake are provided in the present instance by a pair of annular plates 13 rigidly held to the staarmature plate 6 while being connected tionary casing 1 and havinginterposed be-' tween them a third plate 14 fonmed with a central opening for the passage of the shaft '2. The two plates 13 are made to permanently clamp the plate 14 between them with any desired force by means of the bolts 15,

whereby said plates 13 are held to the easing 1, so that by setting up these bolts or unscrewing them, the friction between the coactingfaces of the three plates andconsequently the force retarding any revolution of the plate 14 may be varied to any desired 1 extent. The central opening through this .plate' is substantially circular in outline,

although said plate has inwardly. extending projections or teeth 16; the various parts being so proportioned that the teeth or projections 11' of the sleeve 9 may enter the spaces between the teeth 16 and may co-act with said. teeth to operatively .couple .together said sleeve and said plate. The plates 13 may, if desired, be made of iron or steel. and the plate 14- of brass, or vice-versa, or

. if desired one plate or set of plates may have a suitable metal deposited electrolytically on its working face or faces.

When the various parts are at rest andthe clutch winding 5 is deenergized, the spring 8 holds the armature plate 6 and with it the-sleeve 9, away from the stationary clutch member 4:, but since under operating "conditions, the said winding is preferably connected in series with thearmature of the motor 20 with which'the device is used (Fig.

3) as soon as said motor is started said winding attracts to it the armature plate 6,

so that when the shaft2 turns, the sleeve 9 and said plate are the only parts of the ap-' paratus which revolve. It is obvious that the winding may also be connected across the-supply, mains, 2'. e. in parallel with'the motor. When, however,'the current is cut off from the motor and hence from the clutch winding 5, or is cut off from said winding V at the same'time' thejmotor circuit is opened,

the spring 8 at once forces the plate 6 away from the member 4 and causes the teeth 11 of the sleeve 9 to enter the space between the teeth 16 andthe plate 14:, thereby coupling the shaft 2 and whatevermechanism is at- 'taohed to it, to said-plate.

the two plates 13'tightly grip between them the plate 14, a retarding force is'at once exerted toprevent revolution of the plate 1-):

and shaft 2,' which,'w ith its attached mechanism, is very quickly brought to rest.

In order that .the armature plate 6 may not stick to the plate 13, againstwhich it might beforced by the spring, I provide two or more plugs 17 of brass or other non-magnetic material, preferably mounted in the face of said plate 6. g While thejabove; described device is ,par-

i ticularly useful for preventing drifting of a planer table when the power is cut off from the driving motor, it is obvious that it -may be employed in other combinations without essential modification or 'departure v:r from my: invention It willigbegnoted that thesleeve 9 is of I v relatively small mass, so "that the momentum v $6 of the moving parts of the device is practically negligible,'thereby making possible the stoppin of said parts in a minimum time and wit a minimum braking force.

" yIt is obvious that where a great braking force is required-,mo're than twoplates 13 maybe used and likewise a corresponding said other plates.

Since, however,

number of plates 14 may be alternated with lVhile an electro-magnet is illustrated as the device whereby under certain conditions, one element of the braking device is caused to be connected to or disconnected from the shaft or machine whose movement is to be retarded, it is obvious other devices may be employed for performing this work Without departing from my invention.

As manychanges could be made in the above construction and many apparently widely different embodiments ofthis invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawingsshall be interpreted as illustrative and not in a limiting sense. It is also to be understood that the language used in the. following claims is intended to cover all of the generic and specific features of theinvention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

I-Iavmg described my invention, what I clalm as new' and desire'to secure by Letters Patent is:

1. In a device of the "character described, in combination, a motor comprising a shaft, braking means therefor comprising friction members and a clutch element, a second clutch element adapted to coact therewith to thereb cause saidbraking means to act upon sai shaft, and electromagnetic means mountedon the motor casing and adapted to actuate one of said clutch elements.

2. In a device of the character described,

in combination, a motor comprising a shaft,

braking means therefor comprising a plu.

rality of movable and fixed friction mem- .bers, one of said members being provided with a clutch element, said shaft being provided with a second clutch element adapted to coact with said first-mentioned clutch ele-' ment, and electromagnetic means mounted on the motor casing and adapted to control 4. In a device of the character described,

in combination, a motor comprising a shaft, friction braking means mounted ad acent ,said shaft and provided with a clutch element, a second clutch element movably mounted upon said shaft, means mounted on the motor casing and adapted to move said last-mentioned clutch element into engage ment with said clutch element associated with said braking means to thereby cause a braking action upon said shaft, and elec-- in combination, a motor comprising a shaft,

two engaged and normally'stationary work ing plates, means for automatically connecting said shaft with one of said plates when it is desired to retard movement oft-he shaft, and an electro-magnet mounted on the easing and adapted to throw said connecting means out of connection.

6. In a device of the character described, in combination, a'motor comprising a shaft, two permanently engaged and normally stationary friction plates, automatic means for connecting said shaft with one of said plates to cause braking action under predetermined conditions, and an electro-magnet device for normally maintaining said connecting means out of action.

7. The combination of a motor and braking means therefor including an electromagnet having its winding in circuit with said motor; a plurality of normally stationary and permanently engaged braking structures; with means for automatically coupling one of said braking structures to the movable member of the magnet when the latter is denergized.

8. The combination with an electric motor of an electro-magnet having its winding in series with said motor and its armature connected to a shaft driven by said motor;

I with braking means including two normally stationary and permanently engaged parts; and a device for connecting one of said parts to the shaft when current is cut off from the motor. 7

9. The combination of an electro-magnet having a fixed anda movable element; a member whose movement is to be retarded; two co-acting and normally stationary braking structures; and means connected to the movable magnet element for operatively coupling one of said braking structures and the movable member when'the magnet is deenergized.

10. The combination of a plurality of engaged and normally stationary braking plates; a member whose movement is to be retarded under predetermined conditions; a structure possessing a relatively small mass for temporarily connecting said memher with one of said braking plates when it is desired to retard movement of the member, and an electro-magnetic device for throwing said connecting structure out of action.

1 1. The combination of a plurality df frictionally engaged and stationary braking elements; a shaft connected to mechanism whose movement is to be retarded; an electro-magnet; with a member. controlled by said magnet and possessing relatively small mass for temporarily connecting the shaft with one of the braking element.

12. The combination of a plurality of plates permanently held in frictional. engagement with each other; a shaft connected to mechanism to be retarded; an electromagnet having an armature plate; and means connected to said armature plate for operatively connecting said shaft and certain of said plate to cause them to rotate together.

13. The combination of a plurality of braking plates in permanent frictional en gagement with each other; a shaft concentric with said plates; an electro-magnet having an armature plate; a sleeve attached to said plate and splined to said shaft; said sleeve being capable of connecting certain of the braking plates to the shaft; and a spring normally tending to force said sleeve into its connecting position.

14. The combination of a supporting structure; a plurality of braking plates in permanent frictional engagement with each other, of which one plate is fixed to said supporting structure and another plate is provided with clutch teeth; a shaft connected to the mechanism whose movement is to be retarded; a sleeve splined to said shaft and having teeth capable of co-acting with the teeth of said'braking plate to couple the same to the shaft; an electro-magnet having 'a'casing and a winding, fixed to the supporting structure and provided with an armature plate connected to the sleeve; with a spring acting in opposition to the winding of the magnet and tending to move the sleeve SAMUEL HINE KEEFER.

Witnesses:

J. T. MAoMUnRAY, C. W. BEITER.

c o rrectlon ln Lette r Pdteht No. 1.1625370 0, gjj fliga i' ignlof- Samuel Hin'e Keefr, of Plainfield, New Jersev,

fo 'iIIiPI'OJ'mIIIQ1113infFriction-QBraks, an error appears in the printed specifijation reqxh rin'g hoi'mqt iion iqllbwzglage 2, claim 5, line's 119-121, after the and ofline 121 ahd insert the words i; 'fo theg'gby control the qfkaid btalcihg mans; and that the saijd h fiaad with this ddrrectiol; therein tjhat the same may conf mjp, thvcase in t h e Patent Offib'e. A

an gg agmsg mhaay o; lgm r g 1).; 1 1a.

J. T. NEWTON, 7

Acting Gam a-m qf Patenta. 

